Update admin gem to 1.1.6

* Fix GillSans font stack
Merge pull request #272 from alphagov/bump-admin-gem

Update admin gem to 1.1.6
Allow Editor notes to have tags

www.agileplannerapp.com/boards/173808/cards/5154

Editor's notes were being validated as govspeak
causing safe html checks to fail. We've made an
exception in the SafeHTMLValidator to validate
only govspeak fields:

https://github.com/alphagov/govuk_content_models/pull/236
Move beta flag to be alongside title
Simplify title attributes on links and editions

Title help text isn’t necessary and distracts from table interactions
Add important notes to publication tables

Quickly see important notes without needing to navigate to the
publication
Improve styles of important notes

* Remove divider between title and tabs, the tabs themselves this
distinction
* Give the important note a title and make it less garish
Merge pull request #274 from alphagov/important-notes-tweaks

Improve design of important notes
Consolidate publication table views

* Remove duplicated published edition partial
* Add a little extra logic to publication partial
Merge pull request #273 from alphagov/bump-content-models-for-safe-html-change

Allow Editor notes to have tags
Add migration to import taggings from panopticon.

Requires bump to govuk_content_models.
Merge pull request #275 from alphagov/pub-table-partials

Consolidate publication table views
Form and display of important notes as actions.

Important note model has changed from a string on the Edition model to an
instance of Action, to allow including author and timestamp.
Controller and form to resolve important notes.
Migration to convert important_notes to actions.
Correct reference to note in index view.
Display delete important note alongside buttons

* Prevent wrapping using a new helper class
Integration tests for new important_note behaviour
Bump govuk_content_models version
Merge pull request #277 from alphagov/important_notes

Audit trail for important notes